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<h1 class="title">codeeditor.cpp 示例文件</h1>
<span class="subtitle">widgets/codeeditor/codeeditor.cpp</span>
<!-- $$$widgets/codeeditor/codeeditor.cpp-description -->
<div class="descr"> <a name="details"></a>
<pre class="cpp">

  <span class="comment">/****************************************************************************
  **
  ** Copyright (C) 2016 The Qt Company Ltd.
  ** Contact: https://www.qt.io/licensing/
  **
  ** This file is part of the examples of the Qt Toolkit.
  **
  ** $QT_BEGIN_LICENSE:BSD$
  ** Commercial License Usage
  ** Licensees holding valid commercial Qt licenses may use this file in
  ** accordance with the commercial license agreement provided with the
  ** Software or, alternatively, in accordance with the terms contained in
  ** a written agreement between you and The Qt Company. For licensing terms
  ** and conditions see https://www.qt.io/terms-conditions. For further
  ** information use the contact form at https://www.qt.io/contact-us.
  **
  ** BSD License Usage
  ** Alternatively, you may use this file under the terms of the BSD license
  ** as follows:
  **
  ** &quot;Redistribution and use in source and binary forms, with or without
  ** modification, are permitted provided that the following conditions are
  ** met:
  **   * Redistributions of source code must retain the above copyright
  **     notice, this list of conditions and the following disclaimer.
  **   * Redistributions in binary form must reproduce the above copyright
  **     notice, this list of conditions and the following disclaimer in
  **     the documentation and/or other materials provided with the
  **     distribution.
  **   * Neither the name of The Qt Company Ltd nor the names of its
  **     contributors may be used to endorse or promote products derived
  **     from this software without specific prior written permission.
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  **
  ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  ** &quot;AS IS&quot; AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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  ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.&quot;
  **
  ** $QT_END_LICENSE$
  **
  ****************************************************************************/</span>

  <span class="preprocessor">#include &lt;QtWidgets&gt;</span>

  <span class="preprocessor">#include &quot;codeeditor.h&quot;</span>


  CodeEditor<span class="operator">::</span>CodeEditor(<span class="type"><a href="qwidget.html">QWidget</a></span> <span class="operator">*</span>parent) : <span class="type"><a href="qplaintextedit.html">QPlainTextEdit</a></span>(parent)
  {
      lineNumberArea <span class="operator">=</span> <span class="keyword">new</span> LineNumberArea(<span class="keyword">this</span>);

      connect(<span class="keyword">this</span><span class="operator">,</span> SIGNAL(blockCountChanged(<span class="type">int</span>))<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> SLOT(updateLineNumberAreaWidth(<span class="type">int</span>)));
      connect(<span class="keyword">this</span><span class="operator">,</span> SIGNAL(updateRequest(<span class="type"><a href="../qtcore/qrect.html">QRect</a></span><span class="operator">,</span><span class="type">int</span>))<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> SLOT(updateLineNumberArea(<span class="type"><a href="../qtcore/qrect.html">QRect</a></span><span class="operator">,</span><span class="type">int</span>)));
      connect(<span class="keyword">this</span><span class="operator">,</span> SIGNAL(cursorPositionChanged())<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> SLOT(highlightCurrentLine()));

      updateLineNumberAreaWidth(<span class="number">0</span>);
      highlightCurrentLine();
  }



  <span class="type">int</span> CodeEditor<span class="operator">::</span>lineNumberAreaWidth()
  {
      <span class="type">int</span> digits <span class="operator">=</span> <span class="number">1</span>;
      <span class="type">int</span> max <span class="operator">=</span> <a href="../qtcore/qtglobal.html#qMax">qMax</a>(<span class="number">1</span><span class="operator">,</span> blockCount());
      <span class="keyword">while</span> (max <span class="operator">&gt;</span><span class="operator">=</span> <span class="number">10</span>) {
          max <span class="operator">/</span><span class="operator">=</span> <span class="number">10</span>;
          <span class="operator">+</span><span class="operator">+</span>digits;
      }

      <span class="type">int</span> space <span class="operator">=</span> <span class="number">3</span> <span class="operator">+</span> fontMetrics()<span class="operator">.</span>horizontalAdvance(QLatin1Char(<span class="char">'9'</span>)) <span class="operator">*</span> digits;

      <span class="keyword">return</span> space;
  }



  <span class="type">void</span> CodeEditor<span class="operator">::</span>updateLineNumberAreaWidth(<span class="type">int</span> <span class="comment">/* newBlockCount */</span>)
  {
      setViewportMargins(lineNumberAreaWidth()<span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> <span class="number">0</span>);
  }



  <span class="type">void</span> CodeEditor<span class="operator">::</span>updateLineNumberArea(<span class="keyword">const</span> <span class="type"><a href="../qtcore/qrect.html">QRect</a></span> <span class="operator">&amp;</span>rect<span class="operator">,</span> <span class="type">int</span> dy)
  {
      <span class="keyword">if</span> (dy)
          lineNumberArea<span class="operator">-</span><span class="operator">&gt;</span>scroll(<span class="number">0</span><span class="operator">,</span> dy);
      <span class="keyword">else</span>
          lineNumberArea<span class="operator">-</span><span class="operator">&gt;</span>update(<span class="number">0</span><span class="operator">,</span> rect<span class="operator">.</span>y()<span class="operator">,</span> lineNumberArea<span class="operator">-</span><span class="operator">&gt;</span>width()<span class="operator">,</span> rect<span class="operator">.</span>height());

      <span class="keyword">if</span> (rect<span class="operator">.</span>contains(viewport()<span class="operator">-</span><span class="operator">&gt;</span>rect()))
          updateLineNumberAreaWidth(<span class="number">0</span>);
  }



  <span class="type">void</span> CodeEditor<span class="operator">::</span>resizeEvent(<span class="type"><a href="../qtgui/qresizeevent.html">QResizeEvent</a></span> <span class="operator">*</span>e)
  {
      <span class="type"><a href="qplaintextedit.html">QPlainTextEdit</a></span><span class="operator">::</span>resizeEvent(e);

      <span class="type"><a href="../qtcore/qrect.html">QRect</a></span> cr <span class="operator">=</span> contentsRect();
      lineNumberArea<span class="operator">-</span><span class="operator">&gt;</span>setGeometry(<span class="type"><a href="../qtcore/qrect.html">QRect</a></span>(cr<span class="operator">.</span>left()<span class="operator">,</span> cr<span class="operator">.</span>top()<span class="operator">,</span> lineNumberAreaWidth()<span class="operator">,</span> cr<span class="operator">.</span>height()));
  }



  <span class="type">void</span> CodeEditor<span class="operator">::</span>highlightCurrentLine()
  {
      <span class="type"><a href="../qtcore/qlist.html">QList</a></span><span class="operator">&lt;</span><span class="type"><a href="qtextedit.html">QTextEdit</a></span><span class="operator">::</span>ExtraSelection<span class="operator">&gt;</span> extraSelections;

      <span class="keyword">if</span> (<span class="operator">!</span>isReadOnly()) {
          <span class="type"><a href="qtextedit.html">QTextEdit</a></span><span class="operator">::</span>ExtraSelection selection;

          <span class="type"><a href="../qtgui/qcolor.html">QColor</a></span> lineColor <span class="operator">=</span> <span class="type"><a href="../qtgui/qcolor.html">QColor</a></span>(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>yellow)<span class="operator">.</span>lighter(<span class="number">160</span>);

          selection<span class="operator">.</span>format<span class="operator">.</span>setBackground(lineColor);
          selection<span class="operator">.</span>format<span class="operator">.</span>setProperty(<span class="type"><a href="../qtgui/qtextformat.html">QTextFormat</a></span><span class="operator">::</span>FullWidthSelection<span class="operator">,</span> <span class="keyword">true</span>);
          selection<span class="operator">.</span>cursor <span class="operator">=</span> textCursor();
          selection<span class="operator">.</span>cursor<span class="operator">.</span>clearSelection();
          extraSelections<span class="operator">.</span>append(selection);
      }

      setExtraSelections(extraSelections);
  }



  <span class="type">void</span> CodeEditor<span class="operator">::</span>lineNumberAreaPaintEvent(<span class="type"><a href="../qtgui/qpaintevent.html">QPaintEvent</a></span> <span class="operator">*</span>event)
  {
      <span class="type"><a href="../qtgui/qpainter.html">QPainter</a></span> painter(lineNumberArea);
      painter<span class="operator">.</span>fillRect(event<span class="operator">-</span><span class="operator">&gt;</span>rect()<span class="operator">,</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>lightGray);


      <span class="type"><a href="../qtgui/qtextblock.html">QTextBlock</a></span> block <span class="operator">=</span> firstVisibleBlock();
      <span class="type">int</span> blockNumber <span class="operator">=</span> block<span class="operator">.</span>blockNumber();
      <span class="type">int</span> top <span class="operator">=</span> (<span class="type">int</span>) blockBoundingGeometry(block)<span class="operator">.</span>translated(contentOffset())<span class="operator">.</span>top();
      <span class="type">int</span> bottom <span class="operator">=</span> top <span class="operator">+</span> (<span class="type">int</span>) blockBoundingRect(block)<span class="operator">.</span>height();

      <span class="keyword">while</span> (block<span class="operator">.</span>isValid() <span class="operator">&amp;</span><span class="operator">&amp;</span> top <span class="operator">&lt;</span><span class="operator">=</span> event<span class="operator">-</span><span class="operator">&gt;</span>rect()<span class="operator">.</span>bottom()) {
          <span class="keyword">if</span> (block<span class="operator">.</span>isVisible() <span class="operator">&amp;</span><span class="operator">&amp;</span> bottom <span class="operator">&gt;</span><span class="operator">=</span> event<span class="operator">-</span><span class="operator">&gt;</span>rect()<span class="operator">.</span>top()) {
              <span class="type"><a href="../qtcore/qstring.html">QString</a></span> number <span class="operator">=</span> <span class="type"><a href="../qtcore/qstring.html">QString</a></span><span class="operator">::</span>number(blockNumber <span class="operator">+</span> <span class="number">1</span>);
              painter<span class="operator">.</span>setPen(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>black);
              painter<span class="operator">.</span>drawText(<span class="number">0</span><span class="operator">,</span> top<span class="operator">,</span> lineNumberArea<span class="operator">-</span><span class="operator">&gt;</span>width()<span class="operator">,</span> fontMetrics()<span class="operator">.</span>height()<span class="operator">,</span>
                               <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>AlignRight<span class="operator">,</span> number);
          }

          block <span class="operator">=</span> block<span class="operator">.</span>next();
          top <span class="operator">=</span> bottom;
          bottom <span class="operator">=</span> top <span class="operator">+</span> (<span class="type">int</span>) blockBoundingRect(block)<span class="operator">.</span>height();
          <span class="operator">+</span><span class="operator">+</span>blockNumber;
      }
  }

</pre>
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<!-- @@@widgets/codeeditor/codeeditor.cpp -->
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